LAUSR

The article recently published online [1] in your distinguished journal has subject and discussions that have common aspects with our recently published article [2]. In our article [2], total core length (TCL) was described as the sum of the lengths of cores obtained from each patient. Average core length (ACL) was calculated for each patient separately; it is TCL divided by the total number of cores. Mean core length (MCL) was defined as the mean of the sum of the lengths of all cores (n = 17,074) of the whole cohort pooled together. In our study, TCL (< 120.0 and ≥ 120.0 mm), ACL (< 10.0 and ≥ 10.0, < 11.9 and ≥ 11.9 mm) and MCL (< 10.0 and ≥ 10.0, < 13.0 and ≥ 13.0 mm) were categorized according to the recommended cut-off values indicated in the guidelines [3–5] and the cutoffs (11.9 for ACL and 13.0 for MCL) published in the relevant manuscripts [6, 7]. We clearly showed in the retrospective analysis of consecutive transrectal guided systematic 12 core prostate biopsies including a total of 17,074 cores in 1523 patients that TCL (119.80 ± 30.77 mm vs 115.13 ± 32.35 mm) and ACL (10.59 ± 2.34 mm vs 10.23 ± 2.38 mm) were significantly (p < 0.004 and p < 0.003, respectively) shorter in patients with prostate cancer than without. We also showed that there was a significant indirect relation between increasing prostate volume categories and percent prostate cancer. In other words, percent prostate cancer decreased steadily and significantly (p < 0.001) from 56.1 to 21.7% with increasing PV categories (< 30, 30–59.99, 60–119.99, and ≥ 120 cm3), although MCL (from 9.89 to 11.08 mm), TCL (from 107.85 to 127.48 mm), and ACL (9.83 to 11.07 mm) all steadily and significantly (p < 0.001 for all) increased with increasing PV categories. On the other hand, we failed to show increased detection of prostate cancer in longer biopsy cores when we used cutoffs stated in the current guidelines and published literature for MCL, ACL, and TCL. Prostate cancer detection rate decreased above the cutoffs in all of the studied parameters of MCL (from 19.2 to 18.7% for 10 mm, and from 19.1 to 18.4% for 13 mm cutoff), ACL (from 44.5 to 39.4% for 10 mm, and from 43.4 to 36.2% for 11.9 mm cutoff), and TCL (from 43.4 to 39.6% for 120 mm cutoff) in our study. However, in their study [1], authors examined the impact of biopsy core length on Gleason grade grouping, and tumor recurrence in 2424 biopsy cores in 202 patients who had radical prostatectomy. They also compared biopsy core length in positive and negative cores and in index tumor positive cores and in tumors classified as clinically insignificant. However, whether the “core length” described in their study corresponds to our MCL or ACL is not clear in their manuscript. Their results relevant to our findings in our study showed that core lengths were longer in positive cores (mean 12.6, median 12.7 mm) compared with negative ones (mean 11.3, median 11.4 mm); p value was not given. They also found that core length was longer in index tumor positive cores (p = 0.043) and in tumors classified as clinically insignificant (p = 0.011). Our findings, based on biopsy cores (17,074 vs 2424), are opposite to their findings and the other studies published previously in the literature [6, 7] that core lengths in cancer positive cores are longer than negative ones. Looking at the data presented above, this issue is clearly quite controversial in the literature for the time being. For this reason, we think that additional larger studies are seriously required.